\documentclass[12pt]{article}          % in LaTeX2e 
%\usepackage{multicol}                 % in LaTeX2e, if macro package is to be loaded
% or alternatively in LaTeX2.09 the following line:
%\documentstyle[multicol,12pt]{article} % in LaTeX2.09
%                                      instead of \documentclass and \usepackage
                         % start of preamble; declarations may be placed here
  \textwidth 140mm
  \newcommand{\whenproduced}{This text was produced on \today}
                         % end of preamble
\begin{document}
                         % start of text production
  Text and text producing commands may appear starting here: \whenproduced.
                         % end of text production
\end{document}
